To control the rate of medicament release, and to enhance storage stability and taste-masking effect, various pharmaceutical preparations have been disclosed in which low-melting-point substances (for example, polyglycerol fatty acid esters and glycerol fatty acid esters) are used as matrix base materials.
For example, Japanese Patent No. 2893191 discloses a method for obtaining spherical particles which comprises the steps of fusing a polyglycerol fatty acid-containing matrix, mixing the fused matrix with a medicament, and granulating the mixture by spray-chilling. According to this patent, due to the polyglycerol fatty acid ester, a pharmaceutical preparation with stably controlled medicament release can be prepared. The patent also discloses that by adjusting the HLB (hydrophilic-lipophilic balance) of the polyglycerol fatty acid ester, the rate of medicament release can be controlled.
Japanese Unexamined Patent Publication No. 505841/1996 discloses a drug delivery system with substantially no taste that comprises a medicament with an unpleasant taste, a low-melting-point substance and a hydrophobic polymer.
Japanese Examined Patent Publication No. 47531/1994 discloses particles with a sustained procainamide hydrochloride release prepared by adhering procainamide hydrochloride to the surface of a low-melting-point substance nucleus with heating and, while maintaining the temperature at the melting point of the low-melting-point substance or higher, and adhering talc to surface thereof. This sustained-release particulate is said to have excellent sustained release properties, appearance, strength, stability, etc.
Japanese Patent No. 3124063 discloses particles prepared by heating a granular polyglycerol fatty acid ester having a melting point of 40-80° C. and a powder to fluidize them, thereby reportedly enabling the active ingredient contained in the powder to be steadily released and rendering the active ingredient stabilized over a long period of time.